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F + M � 2.2 December 1998 UST Removal and Soil Removal In December 1998, three 8,000-gallon gasoline USTs and their associated dispensers and piping were removed from the site. Approximately 300 tons of contaminated soil were excavated in the process and later disposed of off-site at the Forward Landfill. During the UST removal operations, samples were collected from the excavation, pipe trenches, stockpiles, and water within the pit. Soil samples collected within the excavation contained up to 33 ppm TPH-G, 0.076 ppm benzene, 0.72 p p m toluene, 0.52 ppm ethyl benzene, 3 ppm total xylenes, and 0.71 p p m MTBE. Soil samples collected within the piping trenches contained up to 160 ppm TPH-G, 0.6 ppm benzene, 1 ppm toluene, 22 ppm ethyl benzene, 220 ppm total xylenes, and 2.5 ppm MTBE. Soil samples collected from the stockpiles contained up to 470 ppm TPH-G, 0.75 ppm benzene, 21 ppm toluene, 7.1 ppm ethyl benzene, 44 ppm total xylenes, 10 ppm MTBE, and 6.5 ppm tertiary butanol (TBA). The groundwater sample collected from the UST excavation contained 66,000 ppb TPH-G, 2,700 p p b benzene, 10,000 ppb toluene, 720 ppb ethyl benzene, 12,000 ppb total xylenes, and 28,000 ppb MTBE. 2-3 1999 UST Jnstallation In early 1999, two 1.0,000 gallon USTs were installed at the site in a different location on the property from the previous USTs. New lines a n d dispensers were also installed. 2-4 Qc ober 2000 CPT DrillinV Site Assessmrn On October 4, 2000, ASE drilled soil borings CPT-1 and CPT-2 at the site using a CPT direct push drill rig (Figure 2). Soil beneath the first water bearing zone, the bottom of which is no deeper than 16-feet bgs, generally consisted of low to very low permeability sediments to a total depth of at least 70-feet bgs. Only a couple of very thin sand or sandy silt lenses, no thicker than ] -foot in thickness, were located in the very low permeability unit. The soil sample collected at 7.0-feet bas in boring CPT-1 contained 260 ppm TPH-G and 0.66 ppm ethyl benzene. The soil Sample collected at 7.0-feet bgs in boring CPT-2 contained 6,500 p p m TPH-G, 12 ppm benzene, 87 ppm toluene, 91 ppm ethyl benzene, 41.0 p p m total xylenes, and 0.56 ppm MTBE. The only compound detected above the laboratory reporting limit in groundwater samples collected from boring CPT-1 was total xylenes at 0.56 ppb in the groundwater sample collected from 41-feet bgs. No groundwater samples could be recovered during a sampling attempt from a sandy silt lens at 57-feet bgs. The 574 West Grant Line Road CAP — January 2002 -2-